<template>
  <div class="spec-preview" @mousemove="mousemove">
    <img :src="skuImageList[choosePicIndex]?.imgUrl" />
    <div class="event"></div>
    <div class="big">
      <img ref="bigImg" :src="skuImageList[choosePicIndex]?.imgUrl" />
    </div>
    <div ref="mask" class="mask"></div>
  </div>
</template>

<script>
  export default {
    name: "Zoom",
    props:["skuImageList","choosePicIndex"],
    mounted() {
      console.log(this.skuImageList,"skuImageList");
    },
    methods:{
      mousemove(e){
        // console.log(e.offsetX,'e.offsetX');
        const maskPositon={
          x:e.offsetX - this.$refs.mask.offsetWidth/2,
          y:e.offsetY - this.$refs.mask.offsetHeight/2
        }
        //x，y不能小于0
        if(maskPositon.x<=0){
          maskPositon.x = 0
        }else if(maskPositon.x>=e.target.clientWidth-this.$refs.mask.offsetWidth){
          maskPositon.x = e.target.clientWidth-this.$refs.mask.offsetWidth
        }
        if(maskPositon.y<=0){
          maskPositon.y = 0
        }else if(maskPositon.y>=e.target.clientHeight-this.$refs.mask.offsetHeight){
          maskPositon.y = e.target.clientHeight-this.$refs.mask.offsetHeight
        }
        this.$refs.mask.style.left = maskPositon.x + "px"
        this.$refs.mask.style.top = maskPositon.y + "px"

        this.$refs.bigImg.style.left = -maskPositon.x*2 + "px"
        this.$refs.bigImg.style.top = -maskPositon.y*2 + "px"
      }
    }
  }
</script>

<style lang="less">
  .spec-preview {
    position: relative;
    width: 400px;
    height: 400px;
    border: 1px solid #ccc;

    img {
      width: 100%;
      height: 100%;
    }

    .event {
      width: 100%;
      height: 100%;
      position: absolute;
      top: 0;
      left: 0;
      z-index: 998;
    }

    .mask {
      width: 50%;
      height: 50%;
      background-color: rgba(0, 255, 0, 0.3);
      position: absolute;
      left: 0;
      top: 0;
      display: none;
    }

    .big {
      width: 100%;
      height: 100%;
      position: absolute;
      top: -1px;
      left: 100%;
      border: 1px solid #aaa;
      overflow: hidden;
      z-index: 998;
      display: none;
      background: white;

      img {
        width: 200%;
        max-width: 200%;
        height: 200%;
        position: absolute;
        left: 0;
        top: 0;
      }
    }

    .event:hover~.mask,
    .event:hover~.big {
      display: block;
    }
  }
</style>